Many different applications are possible for ionization systems. For example, it is desirable to form a pumpless, low mass sampling system for a mass spectrometer.
Conventional mass spectrometers often use xe2x80x9chardxe2x80x9d techniques of producing ion fragments, in which certain parts of the molecule are forcibly removed, to form the fragmented ion. For example, the fragments may be produced by ultraviolet, radioactive, and/or thermal electron ionization techniques. Some of these techniques, and specifically the thermal technique, may require a vacuum to enhance the life of the filament source.
Different systems which use ionization are known. A quadrupole and magnetic sector/time of flight system ionizes a sample to determine its content. These devices have limitations in both operation and size. Many devices of this type may operate over only a relatively small mass sampling range. These devices may also suffer from efficiency issues, that is the ions might not be efficiently formed.
Many of these systems also require a very high vacuum to avoid ion collisions during passage through the instrument. For example, the systems may require a vacuum of the level of such as 10xe2x88x926 Torr. A vacuum pump must be provided to maintain this vacuum. The vacuum pump consumes power, may be heavy, and also requires a relatively leak free environment. This clashes with the usual desire to miniaturize the size of such a device.
Other applications could be desirable for ionization, if an ionization system were sufficiently small. However, the existing ionization systems have problems and difficulties in fabrication which has prevented them from being used in certain applications.
The present application describes a special ionization membrane, along with applications of this special ionization membrane that are facilitated by the membrane.
A first application uses the ionization membrane as part of a mass spectrometer.
Another application uses the ionization membrane for other applications. According to an aspect of this invention, the electrodes are formed closer than the mean free path of a specified gas, for example the gas being considered. This may ionize gas molecules in free space. Different applications of this soft ionization technique are described including using this system in a mass spectrometer system, such as a rotating field mass spectrometer. This may also be used in a time of flight system.
In an embodiment, a pumpless mass spectrometer is described which does not include a pump for either forming the vacuum or for driving the ions.
Another embodiment describes using this system for an electrochemical system. Another application describes using this system in propulsion.